1. Field of the Invention
The present invention relates to an Orthogonal Frequency Division Multiplexing (OFDM) system. More particularly, the present invention relates to a downlink power control method and apparatus of the OFDM system.
2. Description of the Related Art
Mobile communication systems developed to provide subscribers with voice communication services on the move. With the rapid advance of mobile communication technology, the mobile communication systems have evolved to support high speed data communication services as well as the standard voice communication services. However, the limited resource and user requirements for higher speed services in current mobile communication systems has spurred the evolution to more advanced mobile communication system.
In order to accomplish the goals, various next generation mobile communication technologies are being developed. The 3rd Generation Partnership Project (3GPP) is standardizing Long Term Evolution-Advanced (LTE-A). LTE-A is a technology for realizing high speed packet-based communication at about up to 1 Gbps. In order to achieve this, discussion are being held on several schemes such as network multiplexing for deploying multiple evolved Node Bs (eNBs) overlappingly in a specific area and for increasing a number of frequency bands supported by an eNB. However, such a configuration increases the interference between eNBs and thus recent studies are focused on the inter-cell interference control based on the time and frequency division techniques.
In addition to the frequency division technique adopted by LTE, the LTE-A has adopted the time division technique. The time division technique is a method for preventing the high transmission power of an eNB from interfering the User Equipment (UE) served by a neighbor eNB at a specific subframe. In this case, the downlink power control of the eNB having a high transmit power level influences the system throughput and there is therefore a need of an enhanced downlink power control technique.
Therefore, a need exists for a system and method for scheduling the UEs connected to the eNB having a high transmit power level at low power level that is capable of scheduling the UEs efficiently even when there are significant power differences between subframes.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.